The Influence of an External Magnetic Field on a “ Macro ” Hollow Cathode Discharge in Argon

We present some results about the influence of an external axial magnetic field on the parameters of a dc discharge at low pressures in argon with“macro” hollow cathode geometry. These “macro” configurations were helpful for understanding some general properties (discharge regime, I-V characteristics) of micro hollow cathode discharges (MHCD) at high pressure. The same method can be used to study the influence of an external magnetic field on a dc discharge at low pressure in argon with MHCD geometry. Thus, if an axial magnetic field is applied at the open end of the “macro” hollow cathode, the maximum of light emission in the centre of the hole is replaced by an annular ring, probable the first striation of the positive column in coaxial geometry. Also the I-V characteristics are changed at higher pressures in the presence of a strong magnetic field. These results can be applied to MHCD at high pressure and also to miniaturized cylindrical magnetrons.